Improvement in manufacture of chromate of potash



UNITED STATES PATENT OFFICE.

ISAAC TYSON, J[t., OF BALTIMORE, MARYLAND.

IMPROVEMENT IN MANUFACTURE OF CHROMATE OF POTASH.

Specification forming part of Letters Patent No. 3,224, dated October 9,1845.

To all whom it may concern:

Be it known that I, ISAAC TYSON, Jr., of the city of Baltimore, in theState of Maryland, manufacturing chemist, have made a new and usefulImprovement in the Manner of Manufacturing the Salt known under the Nameof Ohromate of Potash and I do hereby declare that the following is afull and exact description thereof.

My improvement in this process consists in the use of a largeproportionate quantity of wood-ashes as a substitute for its equivalentof the carbonate of potash or other alkaline salt; and this substitutionis not made for the mere purpose of lessening the quantity of thealkaline salts of commerce, which it may be necessary to employ, but Ihave proved by careful experiment that a larger quantity of the chromateis obtained from a given weight of the ore when wood-ashes are thus usedthan when the whole of the alkali is supplied by the salts of commerce,the foreign matters contained in the wood-ashes manifestly producingthis effect. In other respects the process is managed as heretofore-thatis to say, the materials are pulverized and then intimately mixed withthe wood-ashes. The proportion of the respective ingredients will ofcourse vary with their purity, which the manufacturers must ascertain bythe usual modes. The proportions which I have generally found to answerwell are one part, by weight, of the chrome ore and of the alkalinesalt, and one and a half part, by weight, of the ordinary wood-ashes. Iwill observe, however, that in my improved process I have found that theheat may be increased with ad vantage.

Having thus fully described the nature of my improvement in the processof manufacturing the salts of chrome, what I claim therein as new, anddesire to secure by Letters Patent, is-

The using of wood-ashes in mixture with the chrome ore and with thealkaline salt, for the purpose and in the manner herein fully set forth.I

ISAAC TYSON, JR.

Witnesses:

WM. M. J ITTON, LLOYD NORRIS.

